1. Field of the Invention
The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus suitable for forming a color image.
2. Related Background Art
As the method for forming a color image on a recording medium such as paper, there is known a method of forming a color image by superposing different colors with ink jet recording, with thermal recording or the like.
If a light transmission film, for example, is used as a recording medium for ink jet recording, there arises the problem that the chromaticity and density of a transmitted color image as observed with transmitted light becomes different from those of a reflected color image as observed with reflected light. The main reason for this is as follows.
Most color ink jet recording apparatus are generally equipped each with four color heads, yellow (Y), magenta (M), cyan (C) and black (BK), and form a color mixture, e.g., green, by jetting out Y and C ink droplets at the same point. The order of jetting out a plurality of colors to form a color mixture has a great effect upon the chromaticity of a reflected color image on a light transmission film. Specifically if Y and C ink droplets are jetted out in this order as shown in FIG. 3, Y ink is absorbed in the film medium at the position nearer to the observation site for a reflected color image, whereas C ink is absorbed at the far position from the observation site. Since Y ink has a greater effect than C ink, the observed reflected color image has a chromaticity of green nearer to Y. In FIG. 3, reference numeral 21 represents an ink absorbing layer of a recording medium, and 20 represents a light transmission film layer which does not absorb ink but is transparent relative to light.
On the contrary, in case of a transmitted color image as observed with transmitted light, the order of jetting out ink droplets has substantially no adverse effects. Therefore, the chromaticity of green of the transmitted color image can be observed nearer to C when compared to the reflected image.
As described above, the chromaticity of a transmitted color image as observed with transmitted light from the back of the film becomes different from that of a reflected color image as observed with reflected light from the film, resulting in image quality deterioration.